The DOCSIS 3.1 standard now allows for different frequency bands to be used for Upstream (US) and Downstream (DS) transmission. Most cable plants in use today have a 42/54 MHz split, meaning that US can be up to 42 MHz and the DS frequencies begin at 54 MHz. In order to provide more upstream bandwidth to customers, DOCSIS 3.1 allows for 42/108, 85/108, and 204/258 MHz diplexer splits. It is desirable to be able to deploy a modem today that works in existing 42/108 MHz plant, and be able to electronically upgrade that modem in the field to work as a 204/258 MHz unit when a cable plant is upgraded. In order to do that, 2 diplex filters may be included in the product, and the product may utilize solid state RF switches to select a diplex filter. The problem with this technology is that the switches themselves are susceptible to lightning surge events. In testing, it is quite common for an RF switch to be partially damaged in such a way that it still passes a signal. Damage to the switch of this type has consequences, and in this application they would produce harmonics in the Downstream band which violated the DOCSIS specifications, and would affect other devices on the cable plant causing outages.
Therefore, a need exists for improving methods and systems for detecting damaged switches.
Like reference numbers and designations in the various drawings indicate like elements.